A preparation method of a thawed myosin lysate freeze-dried powder for frozen meat preservation and application thereof

Abstract

The application discloses a preparation method of a thawed myoplasm enzymolysis product freeze-dried powder for frozen meat preservation and application thereof, and has the characteristics that the method comprises the following steps: 1) collecting juice lost in the process of thawing frozen meat for 48-72 hours, filtering the collected thawing juice to collect filtrate, and the thawing myoplasm component is obtained; 2) sequentially subjecting the thawing myoplasm component to alkaline protease with a mass fraction of 3-5% of the thawing juice and flavor protease with a mass fraction of 3-5% of the thawing juice to obtain an enzymolysis liquid; 3) subjecting the enzymolysis liquid to ultrasonic treatment to obtain an enzymolysis peptide solution uniformly dissolved in water; and 4) centrifuging the enzymolysis peptide solution in an ultrafiltration equipment, collecting filtrate, and obtaining the thawed myoplasm enzymolysis product freeze-dried powder through freeze-drying, so that the method has the advantages of natural components, low sweetness, simple processing technology, and the like, can slow down the quality deterioration problems such as water holding capacity reduction, protein and fat oxidation and the like of minced meat products in the frozen storage process, and prolongs the shelf life of products.

Description

Technical Field

[0001] The present invention relates to the field of frozen meat preservation, in particular to a preparation method and application of a thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder for frozen meat preservation. Background Art

[0002] During the freezing process of fresh meat, ice crystal nucleation and growth exert significant mechanical stress on cellular tissue, leading to aggregation and denaturation of myofibrillar protein structures after thawing, thus reducing the performance of protein gels. It has been reported that the quality properties of heat-induced gels prepared from freeze-thawed myofibrils are significantly reduced, with water retention, hardness, viscoelasticity, and rheological properties all being destroyed. Furthermore, during long-term frozen storage of fresh meat, adverse chemical reactions such as protein denaturation and fat oxidation can easily lead to quality deterioration of the thawed muscle, such as dull color and severe juice loss. Antifreeze agents are substances added to foods to prevent quality deterioration due to freeze damage, and they can help preserve frozen foods for extended periods of time. Current research indicates that exogenous substances such as carbohydrates and hydrolyzed peptides are primarily used for antifreeze regulation of muscle protein, and they are significantly effective in inhibiting ice crystal growth and delaying the degradation of myofibrillar protein properties. However, sugars can increase the sweetness and caloric content of meat products, making it difficult to meet consumers' demand for nutritious and healthy food. Hydrolyzed peptides are currently mainly prepared by enzymatic hydrolysis of fish skin, scales, or bones. The preparation process is cumbersome, time-consuming, and costly, and hydrolysis can produce a bitter taste, severely restricting their application in the meat processing industry. These research results suggest that it is crucial to develop new, practical antifreeze agents to meet the needs of subsequent processing of frozen meat.

[0003] During the thawing process of frozen meat, approximately 8% to 10% of the thawing juice is lost. Water-soluble sarcoplasmic protein, the primary solid component of this lost juice, is wasted in significant quantities. Recycling this sarcoplasmic protein resource at a high value has become a critical issue for meat processing companies. Currently, there are no reports on the use of thawed sarcoplasmic enzymatic hydrolysates as antifreeze agents for the preservation of frozen meat. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a preparation method and application of a freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate for preserving frozen meat, which has natural components, low sweetness, and antifreeze and preservation effects. The powder can slow down the quality deterioration of minced meat products during frozen storage, such as the decline in water retention and oxidation of protein and fat, and extend the shelf life of the product.

[0005] The technical solution adopted by the present invention to solve the above technical problems is: a method for preparing a freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate for preserving frozen meat, comprising the following steps:

[0006] (1) collecting the juice lost during the thawing of frozen meat for 48-72 hours, filtering the collected thawed juice through a 150-250 mesh sieve, and collecting the filtrate, which is the thawed sarcoplasm fraction;

[0007] (2) enzymatically hydrolyzing the thawed sarcoplasm fraction obtained in step (1) with 3-5% by weight of alkaline protease and 3-5% by weight of flavor protease of the thawed juice to obtain an enzymatic hydrolyzate;

[0008] (3) The enzymatic hydrolyzate obtained in step (2) is ultrasonically treated at 50-150W for 5-10 minutes to obtain an enzymatic peptide solution uniformly soluble in water;

[0009] (4) The enzymatic peptide solution obtained in step (3) is placed in an 8-12 kDa ultrafiltration device, centrifuged at 4000-6000 r / min for 10-30 min, the filtrate is collected, and freeze-dried to obtain a thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder.

[0010] Preferably, the mesh size of the sieve in step (1) is 200 meshes.

[0011] Preferably, step (2) is specifically as follows: adjusting the pH of the thawed sarcoplasm fraction collected in step (1) to 8.5-9.5 with baking soda, adding alkaline protease with an activity of 150,000-200,000 U / g protein for enzymatic hydrolysis, the enzymatic hydrolysis temperature is kept constant at 45-55°C, and the enzymatic hydrolysis time is 2-4 hours; then adjusting the pH of the enzymatic hydrolysis solution to 6.0-6.5 with citric acid, adding flavor protease with an activity of 4,000-6,500 U / g protein for enzymatic hydrolysis, the enzymatic hydrolysis temperature is kept constant at 45-55°C, and the enzymatic hydrolysis time is 2-4 hours, to obtain an enzymatic hydrolysis solution.

[0012] Preferably, the molecular weight cut-off of the ultrafiltration device in step (4) is 10 kDa.

[0013] The freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate prepared by the above method is used in the preservation of frozen minced meat products.

[0014] Furthermore, the specific steps are: selecting fresh meat 48-72 hours after slaughter, removing excess fat and tendons, cutting into blocks, placing in a meat grinder and mincing to prepare minced meat; weighing 2-4 kg of minced meat, adding 0.8-2.0% of thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder according to mass percentage, chopping with a chopper for 6-10 minutes, placing in a 4°C cold storage for 6-8 hours, then making meat patties with a meat patty mold, packaging them in polyethylene packaging bags, and freezing them in a -18 to -25°C cold storage.

[0015] Compared with existing technologies, the advantages of the present invention are as follows: the preparation method and application of a freeze-dried powder of thawed sarcoplasmic hydrolysate for frozen meat preservation utilizes waste juice lost during the thawing process as a raw material, effectively utilizing biomass resources and increasing the added value of the raw material; the sarcoplasmic protein contained in the thawed juice primarily exhibits an α-helical structure, and the presence of a large number of hydrophilic amino acids in the protein side chains provides a certain number of sites for binding to water molecules, enhancing the stability of water molecules during freezing and thereby inhibiting ice crystal nucleation. This characteristic imparts excellent antifreeze activity to the sarcoplasmic protein; the application of protein enzymatic hydrolysis and ultrafiltration technology facilitates the separation and purification of thawed juice sarcoplasmic protein, thereby further obtaining more stable small-molecule enzyme-cleaved fragments.

[0016] In summary, the present invention provides a preparation method and application of a freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate for preserving frozen meat, which combines bio-controllable enzymatic hydrolysis, ultrafiltration membrane separation and ultrasonic technology. The operation process is simple, the production conditions are mild, the raw material cost is low, and large-scale industrial production is easy to achieve. The prepared small molecule enzymatic hydrolysate antifreeze agent does not contain any chemical substances and is derived from frozen meat itself. It can be used as a natural antifreeze preservative and can effectively inhibit the quality deterioration of minced meat products during frozen storage. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Schematic diagram of the secondary structure analysis results of thawed sarcoplasmic enzymatic hydrolysate. DETAILED DESCRIPTION

[0018] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0019] 1. Experimental Methods

[0020] 1. Secondary structure analysis of thawed sarcoplasmic hydrolysate: The secondary structure was determined by Raman spectrometry with a scanning range of 500-2000 cm-1, an excitation wavelength of 785 nm, an acquisition time of 5 s, and 40 scans.

[0021] 2. Thawing loss rate: The mass of the meat patty before freezing is recorded as M1. Thaw it 12 hours after the freezing period, wipe off the surface moisture, weigh it and record it as M2. Calculate the thawing loss rate (%) according to the formula: (M1-M2) / M1×100%.

[0022] 3. Cooking loss rate: Put the thawed meat patties into a vacuum bag, seal it, and heat it in a 75°C water bath for 30 minutes. Cool it to room temperature for 10 minutes, then wipe it dry with filter paper. Weigh it again and record it as M3. Calculate the cooking loss rate according to the formula: Cooking loss rate (%) = (M2-M3) / M2×100%.

[0023] 4. Carbonyl determination: Weigh the myofibrillar protein solution (2 mg / mL), add an equal volume of 10 mM DNPH-hydrochloric acid solution, and react in the dark for 1 h. Add trichloroacetic acid solution (10%, w / v) to terminate the reaction. Centrifuge (10,000 g, 5 min) and take the precipitate, add ethanol / ethyl acetate (1:1, v / v), wash three times and centrifuge. Take the precipitate and dissolve it in 6 M guanidine hydrochloride-hydrochloric acid. Incubate at 37 ° C for 15 min. After cooling to room temperature, measure the absorbance of the solution at 370 nm (A 370 ) Carbonyl content was expressed as nmol / mg protein.

[0024] 5. Determination of free thiol groups: Using the DTNB probe method, accurately weigh 0.5 mL of myofibrillar protein solution (1 mg / mL), add 9 volumes of phosphate buffer containing 8 M urea (0.1 mol / L K2HPO4, 0.01 mol / L EDTA, pH 6.0), then add 100 μL of buffer containing 0.01 mol / L DTNB (0.01 mol / L KH2PO4, pH 6.0), shake and mix, then let it stand for 30 minutes, and measure the absorbance at 412 nm using a spectrophotometer. According to the absorption coefficient of 13600 mol / L, the absorbance of the sample was 0.01 mol / L. -1 cm -1 The free thiol content was calculated and finally expressed as nmol / mg protein.

[0025] 6. Determination of thiobarbituric acid reaction value (TBARS): According to GB 5009.181-2016 "National Food Safety Standard - Determination of Malondialdehyde in Foods", the results are expressed as mg / kg. 2. Specific embodiments

[0027] Example 1

[0028] A method for preparing a freeze-dried powder of thawed sarcoplasmic hydrolysate for preserving frozen meat and its application in the freezing and preservation of minced pork products comprises the following steps:

[0029] (1) The design is to collect the waste juice lost during the 48-hour thawing process of frozen meat from the factory, filter the thawed juice through a 200-mesh sieve, and refrigerate it in a cold storage at 4°C for later use;

[0030] (2) taking the thawed sarcoplasm fraction collected in step (1), adjusting the pH to 8.5-9.5 with baking soda in the first step of enzymatic hydrolysis, adding alkaline protease (150,000-200,000 U / g protein) to carry out enzymatic hydrolysis reaction, the enzymatic hydrolysis temperature is constant at 50°C, and the enzymatic hydrolysis time is 2-4 hours; in the second step of enzymatic hydrolysis, adjusting the pH of the enzymatic hydrolysis solution to 6.0-6.5 with citric acid, adding flavor protease (4,000-6,500 U / g protein) to carry out enzymatic hydrolysis reaction, the enzymatic hydrolysis temperature is constant at 50°C, and the enzymatic hydrolysis time is set to 2-4 hours; then, the amount of each enzyme added is 3-5% of the content of the thawed juice, collecting the enzymatic hydrolysis solution, and refrigerating it in a cold storage at 4°C for later use;

[0031] (3) The enzymatic hydrolysate collected in step (2) was subjected to 100W ultrasonic treatment for 8 minutes to obtain a thawed sarcoplasmic enzymatic peptide solution uniformly dissolved in water, which was refrigerated in a 4°C cold storage for later use;

[0032] (4) placing the enzymatic peptide solution obtained in step (3) in a 10 kDa ultrafiltration device, centrifuging at 5000 r / min for 20 min to retain small molecule enzymatic hydrolysates less than 10 kDa, and freeze-drying to obtain thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder, which was frozen in a -20°C cold storage for later use;

[0033] (5) Fresh pork 48 hours after slaughter was selected, excess fat and tendons removed, and minced into chunks. The minced pork was then minced in a meat grinder to prepare minced meat. Weigh 2 kg of minced meat, add 2% by mass of thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder, mince the minced meat for 6 minutes, and place in a 4°C freezer for 6 hours. Patties were then formed using a patty mold, packaged in polyethylene bags, and stored in a -20°C freezer for 6 months.

[0034] Example 2

[0035] A method for preparing a freeze-dried powder of thawed sarcoplasmic hydrolysate for preserving frozen meat and its application in the freezing and preservation of ground beef products comprises the following steps:

[0036] (1) The design is to collect the waste juice lost during the 48-hour thawing process of frozen meat from the factory, filter the thawed juice through a 200-mesh sieve, and refrigerate it in a cold storage at 4°C for later use;

[0037] (2) taking the thawed sarcoplasm fraction collected in step (1), adjusting the pH to 8.5-9.5 with baking soda in the first step of enzymatic hydrolysis, adding alkaline protease (150,000-200,000 U / g protein) to carry out enzymatic hydrolysis reaction, the enzymatic hydrolysis temperature is constant at 50°C, and the enzymatic hydrolysis time is 2-4 hours; in the second step of enzymatic hydrolysis, adjusting the pH of the enzymatic hydrolysis solution to 6.0-6.5 with citric acid, adding flavor protease (4,000-6,500 U / g protein) to carry out enzymatic hydrolysis reaction, the enzymatic hydrolysis temperature is constant at 50°C, and the enzymatic hydrolysis time is set to 2-4 hours; then, the amount of each enzyme added is 3-5% of the content of the thawed juice, collecting the enzymatic hydrolysis solution, and refrigerating it in a cold storage at 4°C for later use;

[0038] (3) The enzymatic hydrolysate collected in step (2) was subjected to 50W ultrasonic treatment for 10 minutes to obtain a thawed sarcoplasmic enzymatic peptide solution uniformly dissolved in water, which was refrigerated in a 4°C cold storage for later use;

[0039] (4) placing the enzymatic peptide solution obtained in step (3) in a 10 kDa ultrafiltration device, centrifuging at 5000 r / min for 20 min to retain small molecule enzymatic hydrolysates less than 10 kDa, and freeze-drying to obtain thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder, which was frozen in a -20°C cold storage for later use;

[0040] (5) Fresh beef 72 hours after slaughter was selected, excess fat and tendons removed, and minced into chunks. The minced meat was then minced in a meat grinder to prepare minced meat. 4 kg of minced meat was weighed, 1.4% by mass of thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder was added, and the minced meat was minced in a chopper for 10 minutes. The minced meat was then placed in a 4°C freezer for 8 hours. Patties were then formed using a patty mold, packaged in polyethylene bags, and stored in a -25°C freezer for 6 months.

[0041] Example 3

[0042] A method for preparing a freeze-dried powder of thawed sarcoplasmic hydrolysate for preserving frozen meat and its application in the freezing and preservation of chicken mince products comprises the following steps:

[0043] (1) The design is to collect the waste juice lost during the 48-hour thawing process of frozen meat from the factory, filter the thawed juice through a 200-mesh sieve, and refrigerate it in a cold storage at 4°C for later use;

[0044] (2) taking the thawed sarcoplasm fraction collected in step (1), adjusting the pH to 8.5-9.5 with baking soda in the first step of enzymatic hydrolysis, adding alkaline protease (150,000-200,000 U / g protein) to carry out enzymatic hydrolysis reaction, the enzymatic hydrolysis temperature is constant at 50°C, and the enzymatic hydrolysis time is 2-4 hours; in the second step of enzymatic hydrolysis, adjusting the pH of the enzymatic hydrolysis solution to 6.0-6.5 with citric acid, adding flavor protease (4,000-6,500 U / g protein) to carry out enzymatic hydrolysis reaction, the enzymatic hydrolysis temperature is constant at 50°C, and the enzymatic hydrolysis time is set to 2-4 hours; then, the amount of each enzyme added is 3-5% of the content of the thawed juice, collecting the enzymatic hydrolysis solution, and refrigerating it in a cold storage at 4°C for later use;

[0045] (3) The enzymatic hydrolysate collected in step (2) was subjected to ultrasonic treatment at 150W for 5 minutes to obtain a thawed sarcoplasmic enzymatic peptide solution uniformly dissolved in water, which was refrigerated in a cold storage at 4°C for later use;

[0046] (4) placing the enzymatic peptide solution obtained in step (3) in a 10 kDa ultrafiltration device, centrifuging at 5000 r / min for 20 min to retain small molecule enzymatic hydrolysates less than 10 kDa, and freeze-drying to obtain thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder, which was frozen in a -20°C cold storage for later use;

[0047] (5) Fresh chicken meat 48 hours after slaughter was selected, excess fat and tendons removed, and minced into chunks. The minced meat was then minced in a meat grinder to prepare minced meat. 3 kg of minced meat was weighed, 0.8% by mass of thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder was added, and the meat was minced in a chopper for 8 minutes. The meat was then placed in a 4°C refrigerator for 7 hours. Patties were then formed using a patty mold, packaged in polyethylene bags, and stored in a -20°C refrigerator for 6 months.

[0048] Comparative Example 1

[0049] The same method as Example 1 above differs in that no antifreeze is added to the ground pork before freezing. Fresh pork, 48 hours after slaughter, is selected, excess fat and tendons removed, cut into chunks, and minced in a meat grinder to prepare ground meat. 2 kg of ground meat is weighed, minced in a chopper for 6 minutes, and then placed in a 4°C freezer for 6 hours. Patties are then formed using a patty mold, packaged in polyethylene bags, and frozen in a -20°C freezer for 6 months.

[0050] Comparative Example 2

[0051] This method is similar to Example 1 above, except that 2.0% by weight of a sucrose and sorbitol complex is added to the ground pork before freezing, replacing the thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder. Fresh pork, 48 hours after slaughter, is removed of excess fat and tendons, cut into chunks, and minced in a meat grinder to prepare the ground meat. 2 kg of ground meat is weighed, and 2% by weight of a sucrose and sorbitol complex is added, as determined by the percentage. The meat is then minced in a blender for 6 minutes and placed in a 4°C freezer for 6 hours. Patties are then formed using a patty mold, packaged in polyethylene bags, and frozen in a -20°C freezer for 6 months.

[0052] Comparative Example 3

[0053] The same as the above-mentioned embodiment 2, except that no antifreeze is added before the ground beef is frozen.

[0054] Comparative Example 4

[0055] The method is the same as the above-mentioned Example 2, except that 1.4% by weight of a sucrose and sorbitol complex is added before freezing the ground beef, instead of thawing the lyophilized powder of the sarcoplasmic enzymatic hydrolysate.

[0056] Comparative Example 5

[0057] The same as the above-mentioned embodiment 3, except that no antifreeze is added to the chicken mince before freezing.

[0058] Comparative Example 6

[0059] The same as the above-mentioned Example 3, except that 0.8% by mass of a sucrose and sorbitol complex is added before freezing the chicken mince, instead of thawing the lyophilized powder of the sarcoplasmic enzymatic hydrolysate.

[0060] 3. Analysis of experimental results

[0061] 1. Analysis of secondary structure of thawed sarcoplasmic hydrolysate

[0062] like Figure 1 As shown, the study found that the thawed sarcoplasmic hydrolysate obtained was rich in α-helix and β-sheet structures, with relative contents reaching about 20% and 40% respectively.

[0063] 2. Analysis of product results of the embodiment

[0064] 2.1 Example 1 The changes in quality indicators of frozen pork mince patties during frozen storage are shown in Table 1.

[0065] Table 1 Quality changes of frozen pork mince during storage

[0066]

[0067] As shown in Table 1, the use of thawed sarcoplasmic hydrolysate as an antifreeze effectively improved the quality degradation of frozen pork mince during frozen storage. Both thawing loss and cooking loss increased significantly with prolonged frozen storage, indicating severe damage to the muscle cell structure and a decrease in water holding capacity during freezing. Compared to the blank control group, Example 1, thawing loss and cooking loss after six months of frozen storage were reduced by 27.6% and 12.0%, respectively, and the effect was similar to that of the sucrose and sorbitol composite antifreeze in Example 2. Furthermore, analysis of protein oxidation and denaturation indicators, carbonyl and free sulfhydryl values, showed that the addition of thawed sarcoplasmic hydrolysate effectively inhibited the oxidative deterioration of myofibrillar protein during frozen storage of pork mince. Compared to the blank control group, Example 1, after six months of frozen storage, the carbonyl value decreased by 25.2% and the free sulfhydryl value increased by 22.2%, both slightly superior to the sucrose and sorbitol composite antifreeze group in Example 2. The fat oxidation index TBARS shows that the TBARS value of Example 1 is reduced by 19.2% compared with that of Comparative Example 1 and by 9.3% compared with that of Comparative Example 2, indicating that the thawed sarcoplasmic hydrolysate can be used as an antifreeze to inhibit fat oxidation during frozen storage of pork mince.

[0068] 2.2 Example 2 The changes in quality indicators of frozen beef mince patties during frozen storage are shown in Table 2.

[0069] Table 2 Quality changes of frozen beef mince patties during frozen storage

[0070]

[0071] As shown in Table 2, the thawed sarcoplasmic hydrolysate as an antifreeze agent effectively improved the quality deterioration problem of frozen beef mince patties during frozen storage. Compared with the blank group, Example 3, the thawing loss and cooking loss of the beef mince patties in Example 2 were reduced by 25.7% and 7.1% respectively after 6 months of frozen storage, which is close to the effect of the sucrose and sorbitol composite antifreeze agent in Example 4. The degree of protein and fat oxidation in the beef mince patties in Example 2 during frozen storage was significantly lower than that in Example 3 and slightly lower than that in Example 4, which shows the antifreeze protection effect of the thawed sarcoplasmic hydrolysate as an antifreeze agent for beef mince protein and fat. According to the results of protein oxidation and denaturation indicators carbonyl and free thiol, compared with Example 3, the carbonyl value of Example 2 decreased by 25.9% and the free thiol value increased by 26.4% after 6 months of frozen storage, and was slightly better than the sugar alcohol antifreeze group in Example 4. According to the analysis of the fat oxidation index TBARS, compared with Comparative Example 3, the TBARS value of Example 2 was reduced by 29.0%, and compared with the sugar alcohol antifreeze group of Comparative Example 4, the TBARS value of Example 2 was reduced by 7.3%.

[0072] 2.3 Example 3 The changes in quality indicators of frozen chicken mince patties during frozen storage are shown in Table 3.

[0073] Table 3 Quality changes of frozen chicken mince patties during frozen storage

[0074]

[0075]

[0076] As can be seen from Table 3, the thawed sarcoplasmic hydrolysate as an antifreeze agent effectively improved the quality deterioration problem of frozen chicken mince during frozen storage. Compared with the blank group comparative example 5, the thawing loss and cooking loss of the chicken mince in Example 3 were reduced by 24.4% and 10.7% respectively after 6 months of frozen storage, which is close to the effect of the sugar alcohol antifreeze group in comparative example 6. The degree of protein and fat oxidation in the chicken mince in Example 3 during frozen storage was significantly lower than that in comparative example 5 and slightly lower than that in comparative example 6, which shows the antifreeze protection effect of the thawed sarcoplasmic hydrolysate as an antifreeze agent on chicken mince protein and fat. According to the analysis of protein oxidation and denaturation indicators carbonyl and free thiol, compared with the blank group comparative example 5, the carbonyl value of Example 3 decreased by 20.1% and the free thiol value increased by 25.6% after 6 months of frozen storage, and was slightly better than the sugar alcohol antifreeze group in comparative example 6. According to the analysis of TBARS, an index of fat oxidation, the TBARS value of Example 3 was reduced by 31.9% compared with that of Comparative Example 5, and the TBARS value of Example 3 was reduced by 8.6% compared with that of the sugar alcohol antifreeze group of Comparative Example 6.

[0077] In summary, the thawed sarcoplasmic hydrolysate described in the present invention has a certain antifreeze and fresh-keeping effect as an antifreeze agent for minced pork, minced beef and minced chicken products, can significantly inhibit their quality deterioration during long-term frozen storage, reduce the thawing loss rate, enhance water holding capacity, and inhibit protein and lipid oxidation. The antifreeze effect shows a trend of being slightly better than that of commonly used sugar alcohol antifreeze agents.

[0078] The above description is not intended to limit the present invention, and the present invention is not limited to the above examples. Any changes, modifications, additions or substitutions made by persons of ordinary skill in the art within the spirit and scope of the present invention shall also fall within the scope of protection of the present invention.

Claims

1. A method for preparing a freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate for preserving frozen meat, characterized in that The following steps are involved: (1) collecting the juice lost during the thawing of frozen meat for 48-72 hours, filtering the collected thawed juice through a 150-250 mesh sieve, and collecting the filtrate, which is the thawed sarcoplasm fraction; (2) enzymatically hydrolyzing the thawed sarcoplasm fraction obtained in step (1) with 3-5% by weight of alkaline protease and 3-5% by weight of flavor protease of the thawed juice to obtain an enzymatic hydrolyzate; (3) The enzymatic hydrolyzate obtained in step (2) is ultrasonically treated at 50-150W for 5-10 minutes to obtain an enzymatic peptide solution uniformly soluble in water; (4) The enzymatic peptide solution obtained in step (3) is placed in an 8-12 kDa ultrafiltration device, centrifuged at 4000-6000 r / min for 10-30 min, the filtrate is collected, and freeze-dried to obtain a thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder.

2. The method for preparing a freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate for preserving frozen meat according to claim 1, characterized in that: The mesh size of the sieve in step (1) is 200 meshes.

3. The method for preparing a freeze-dried powder of thawed sarcoplasmic hydrolysate for preserving frozen meat according to claim 1, characterized in that The thawed sarcoplasm fraction collected in step (1) is adjusted to a pH of 8.5-9.5 with baking soda, and an alkaline protease with an activity of 150,000-200,000 U / g protein is added for enzymatic hydrolysis, the enzymatic hydrolysis temperature is kept constant at 45-55°C, and the enzymatic hydrolysis time is 2-4 hours; then, the pH of the enzymatic hydrolysis solution is adjusted to 6.0-6.5 with citric acid, and a flavor protease with an activity of 4,000-6,500 U / g protein is added for enzymatic hydrolysis, the enzymatic hydrolysis temperature is kept constant at 45-55°C, and the enzymatic hydrolysis time is 2-4 hours to obtain an enzymatic hydrolysis solution.

4. The method for preparing a freeze-dried powder of thawed sarcoplasmic enzymatic hydrolysate for preserving frozen meat according to claim 1, characterized in that: The molecular weight cut-off of the ultrafiltration device in step (4) is 10 kDa.

5. Use of a freeze-dried powder of thawed sarcoplasmic hydrolysate prepared by the method of claim 1 in preserving frozen minced meat products.

6. The use of the thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder according to claim 5 in the preservation of frozen minced meat products, characterized in that The specific steps are as follows: fresh meat 48-72 hours after slaughter is selected, excess fat and tendons are removed, the meat is cut into blocks, and the blocks are minced in a meat grinder to prepare minced meat; 2-4 kg of the minced meat is weighed, 0.8-2.0% of thawed sarcoplasmic enzymatic hydrolysate freeze-dried powder is added according to the mass percentage, the meat is minced with a chopper for 6-10 minutes, the meat is placed in a 4°C cold storage for 6-8 hours, and then meat patties are made using a meat patty mold, the meat patties are packed in polyethylene packaging bags, and the meat is frozen in a -18 to -25°C cold storage.

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